As an ultrasensitive sensing technology,the application of surface enhanced Raman spectroscopy(SERS)is one interesting topic of nano-optics,which has huge application prospectives in plenty of research fields.In recen...As an ultrasensitive sensing technology,the application of surface enhanced Raman spectroscopy(SERS)is one interesting topic of nano-optics,which has huge application prospectives in plenty of research fields.In recent years,the bottleneck in SERS application could be the fabrication of SERS substrate with excellent enhancement.In this work,a two-dimensional(2D)Ag nanorice film is fabricated by self-assembly method as a SERS substrate.The collected SERS spectra of various molecules on this 2D plasmonic film demonstrate quantitative detection could be performed on this SERS substrate.The experiment data also demonstrate this 2D plasmonic film consisted of anisotropic nanostructures has no obvious SERS polarization dependence.The simulated electric field distribution points out the SERS enhancement comes from the surface plasmon coupling between nanorices.And the SERS signals is dominated by molecules adsorbed at different regions of nanorice surface at various wavelengths,which could be a good near IR SERS substrate for bioanalysis.Our work not only enlarges the surface plasmon properties of metal nanostructure,but also exhibits the good application prospect in SERS related fields.展开更多
Melamine is one of the most frequently detected adulterants in dairy products.The current study proposes a surface-enhanced Raman spectroscopy(SERS)-based analytical tool for fast and reliable screening of melamine in...Melamine is one of the most frequently detected adulterants in dairy products.The current study proposes a surface-enhanced Raman spectroscopy(SERS)-based analytical tool for fast and reliable screening of melamine in bovine milk.A hand-held Raman spectrometer was used in conjunction with a substrate composed of silver nanoparticles(AgNPs)that was 2D printed onto glass fiber(GF)filter paper.Under optimized conditions,a sensitive and fingerprint-like signal at 674 cm^(-1) was obtained.The AgNPs/GF substrate exhibited high sensitivity to melamine in milk down to 1.9498×10^(-5)mg/mL,which is well below the USA and EU safety limits(2.5×10^(-3)mg/mL).Remarkably,the proposed technology was also highly reproducible,showing spot-to-spot and block-to-block variations below 3.3%and 4.9%at 674 cm^(-1) in Raman intensity,respectively.The characteristic peak intensity and concentration of melamine showed an acceptable linear relationship(R^(2)=0.9909)within the range of 0.0001-1 mg/mL.Overall,the method established in this study can provide an efficient and effective method for the quantitative target screening and detection of melamine in dairy products.展开更多
A two-dimensional(2D)surface-enhanced Raman scattering(SERS)substrate is fabricated by decorating carbon nanotube(CNT)films with Ag nanoparticles(Ag NPs)in different sizes,via simple and low-cost chemical reduction me...A two-dimensional(2D)surface-enhanced Raman scattering(SERS)substrate is fabricated by decorating carbon nanotube(CNT)films with Ag nanoparticles(Ag NPs)in different sizes,via simple and low-cost chemical reduction method and self-assembling method.The change of Raman and SERS activity of carbon nanotubes/Ag nanoparticles(CNTs/Ag NPs)composites with varying size of Ag NPs are investigated by using rhodamine 6G(R6G)as a probe molecule.Meanwhile,the scattering cross section of Ag NPs and the distribution of electric field of CNTs/Ag NPs composite are simulated through finite difference time domain(FDTD)method.Surface plasmon resonance(SPR)wavelength is redshifted as the size of Ag NPs increases,and the intensity of SERS and electric field increase with Ag NPs size increasing.The experiment and simulation results show a Raman scattering enhancement factor(EF)of 108for the hybrid substrate.展开更多
基金Project supported by the National Natural Science Foundation of China (Grant No. 11974067)Natural Scienceof CQ CSTC (Grant Nos. cstc2019jcyj-msxmX0145, cstc2019jcyj-bshX0042, and cstc2019jcyj-msxmX0828)Sharing Fund of Chongqing University&Large-scale Equipment
文摘As an ultrasensitive sensing technology,the application of surface enhanced Raman spectroscopy(SERS)is one interesting topic of nano-optics,which has huge application prospectives in plenty of research fields.In recent years,the bottleneck in SERS application could be the fabrication of SERS substrate with excellent enhancement.In this work,a two-dimensional(2D)Ag nanorice film is fabricated by self-assembly method as a SERS substrate.The collected SERS spectra of various molecules on this 2D plasmonic film demonstrate quantitative detection could be performed on this SERS substrate.The experiment data also demonstrate this 2D plasmonic film consisted of anisotropic nanostructures has no obvious SERS polarization dependence.The simulated electric field distribution points out the SERS enhancement comes from the surface plasmon coupling between nanorices.And the SERS signals is dominated by molecules adsorbed at different regions of nanorice surface at various wavelengths,which could be a good near IR SERS substrate for bioanalysis.Our work not only enlarges the surface plasmon properties of metal nanostructure,but also exhibits the good application prospect in SERS related fields.
基金supported by National Natural Science Foundation of China(21804058)Shanxi Scholarship Council of China(2021-068)+1 种基金Shanxi Agricultural University High-Level Talent Project(2021XG013)Shanxi Postdoc Reward(SXBYKY2022001).
文摘Melamine is one of the most frequently detected adulterants in dairy products.The current study proposes a surface-enhanced Raman spectroscopy(SERS)-based analytical tool for fast and reliable screening of melamine in bovine milk.A hand-held Raman spectrometer was used in conjunction with a substrate composed of silver nanoparticles(AgNPs)that was 2D printed onto glass fiber(GF)filter paper.Under optimized conditions,a sensitive and fingerprint-like signal at 674 cm^(-1) was obtained.The AgNPs/GF substrate exhibited high sensitivity to melamine in milk down to 1.9498×10^(-5)mg/mL,which is well below the USA and EU safety limits(2.5×10^(-3)mg/mL).Remarkably,the proposed technology was also highly reproducible,showing spot-to-spot and block-to-block variations below 3.3%and 4.9%at 674 cm^(-1) in Raman intensity,respectively.The characteristic peak intensity and concentration of melamine showed an acceptable linear relationship(R^(2)=0.9909)within the range of 0.0001-1 mg/mL.Overall,the method established in this study can provide an efficient and effective method for the quantitative target screening and detection of melamine in dairy products.
基金the National Natural Science Foundation of China(Grant No.61875024)the Natural Science Foundation of Chongqing,China(Grant Nos.cstc2019jcyjmsxm X0639 and cstc2020jcyj-msxm0605)the Scientific and Technology Research Program of Chongqing Municipal Education Commission,China(Grant Nos.KJQN202000648 and KJQN201900602)。
文摘A two-dimensional(2D)surface-enhanced Raman scattering(SERS)substrate is fabricated by decorating carbon nanotube(CNT)films with Ag nanoparticles(Ag NPs)in different sizes,via simple and low-cost chemical reduction method and self-assembling method.The change of Raman and SERS activity of carbon nanotubes/Ag nanoparticles(CNTs/Ag NPs)composites with varying size of Ag NPs are investigated by using rhodamine 6G(R6G)as a probe molecule.Meanwhile,the scattering cross section of Ag NPs and the distribution of electric field of CNTs/Ag NPs composite are simulated through finite difference time domain(FDTD)method.Surface plasmon resonance(SPR)wavelength is redshifted as the size of Ag NPs increases,and the intensity of SERS and electric field increase with Ag NPs size increasing.The experiment and simulation results show a Raman scattering enhancement factor(EF)of 108for the hybrid substrate.
